I eventually developed a method of tightening the belt from above by using a standard alternator belt tool and a ½ inch socked wrench... as my bet seemed to come loose WAY too often.
As It turned out the bracket holding the alternator lover mounting had become oval, and thus it was impossible to get the belt to run "straight".
So i would either have to get the belt REAL tight and listen to it grind away.. or live with very pronounced and embarrassing whining from the belt on start up.
And sadly the bracket cannot be replaced with the engine in place as the bolts go all the way through the timing chain cover (I am considering drilling some small holes in the inner wing/splash guard to be able to extract the bolts anyway.
But... back to the topic.... love your solution th the problem! good job